The results heartened left-of-center activists, who see a path going forward for circumventing Republican-controlled legislatures. With the new Congress deeply split along partisan lines, the outcome ensured that the states will serve as pivotal battlegrounds for social issues heading toward the next election in 2020.

One of the strongest messages emerging from the results is that voters are eager to make the political process, including voting itself, fairer and more accessible.

Michigan, Missouri and Colorado approved changes in redistricting policy aimed at reducing partisan gerrymandering through the use of independent map-drawers. A similar measure in Utah was leading in partial returns.

Voters in Michigan, Maryland and Nevada supported measures calling for automatic or same-day voter registration. Several states approved new oversight of politicians' ethics. And in Florida, there was decisive approval of a measure that will enable an estimated 1.4 million people with prior felony convictions to regain their voting rights.

"We see strong support for these initiatives from independents, Democrats and Republicans," said Karen Hobert Flynn, president of Common Cause. "The question is whether incumbent officials will wake up to understand that people really do want democracy and that power belongs to the people."

In two Republican-leaning states, Idaho and Nebraska, voters approved measures to expand Medicaid health coverage to tens of thousands of low-income residents, while a similar measure was leading in Utah. In those states, Republican-led legislatures had refused to take advantage of expanded coverage offered under President Barack Obama's health care law.

Other notable results:

— Michigan voters approved legalization of marijuana for recreational use, making it the first Midwestern state to do so. North Dakota rejected a similar measure, while Missouri voters backed legalization of medical marijuana.

— A minimum wage increase was approved in two states. An Arkansas measure will raise the wage from $8.50 an hour to $11 by 2021; Missouri's hourly minimum will gradually rise from $7.85 to $12.

— Louisiana voters overwhelmingly approved making a unanimous jury a requirement for convictions, scrapping a law dating from the era of racial segregation that allowed for split juries.

— Arizona voters rejected a massive expansion of the state's private school voucher program criticized as a move to drain money from public schools and give it to rich parents to fund their kids' private school tuition.

Abortion was on the ballot in three states — one voting to protect access to abortion, the other two backing anti-abortion measures.

In Oregon, voters soundly rejected a measure that would have banned the use of public money to pay for abortion coverage. The measure would have left low-income women on the state's Medicaid plan to pay out-of-pocket for abortions and would have eliminated abortion coverage for public employees such as teachers and firefighters who receive health coverage under a state plan.

"I couldn't be more proud of our state," said Grayson Dempsey, executive director of NARAL Pro-Choice Oregon. "Oregonians showed up for reproductive rights access and made it very clear that we will not back down."

In contrast, West Virginia voters approved a constitutional amendment allowing lawmakers to restrict or outlaw state funding for Medicaid abortions. In Alabama, voters added anti-abortion language to the state's 1901 constitution specifying that Alabama recognizes the "rights of unborn children."

The measure does not affect abortion access unless Roe v. Wade, the U.S. Supreme Court decision that legalized abortion, is reversed — an outcome considered more likely since the addition of conservative Justice Brett Kavanaugh to the high court.

"Both Alabama and West Virginia have teed up state legislators to decimate abortion rights in their states and set up legal challenges that could undermine or overturn Roe on the federal level," said Elizabeth Nash of the Guttmacher Institute, which supports abortion rights. "Alabama in particular approved intentionally vague language in their rollback, making it easier to criminalize abortion and pregnancy and undermine women's health and rights."

One of the biggest ballot-measure victories for liberal activists came in Massachusetts, where voters rejected a conservative-backed attempt to repeal a 2016 state law extending nondiscrimination protections to transgender people.

Similarly, Oregon voters rejected a measure that would have repealed the first-in-the-nation immigrant sanctuary law. That law, adopted in 1987, prevents state and local law enforcement agencies from detaining people who are in the U.S. illegally but have not broken other laws.

Jim Ludwick, one of the founders of the unsuccessful repeal movement, said he was disappointed but noted that his campaign was outspent 20-to-1.

"We're regular citizens, we did our best and we didn't succeed. We're not done," he said. "I fear for my kids and grandkids, particularly here in Oregon. They're getting marginalized."